A need exists for apparatus capable of performing in-line printing on packages for products. Bar codes, date of manufacture and similar messages printed on packages in machine readable form are used for inventory control and pricing of products.
Heretofore, printing operations have been performed off-line as a separate operation from the packaging operation. Bags are often constructed and printed prior to delivery to baggers and packaging devices. Pre-printed labels are often applied to packages after the products have been enclosed.
In many packaging operations, a package is formed around the product, for example buns, in a continuous sequence of operations as the products are cooked, sorted, counted or weighed, and positioned to be sealed in a package formed when seal bars engage webs of film material.
Introduction of slack into the system during any phase of the packaging operation can cause trouble in the packaging line affecting other components on the line.